Because Aspergillus oryzae included in Genus Aspergillus fungi as main members have been used to produce fermented foods or various useful materials since ancient times, and their safety has been proved with the experience of many years, they have recently been utilized broadly as hosts of useful proteins produced by genetic engineering techniques.
In breeding Genus Aspergillus fungi for industrial uses, genetic engineering techniques are very effective to confer desired traits to the fungi. In these genetic engineering techniques, a selection marker is necessary to effectively select transformants with desired traits.
The reported selection markers for filamentous fungi are drug-resistant genes such as hygromycin B-resistant gene (Gene. 1987; 56(1): 117-24) or pyrithiamine-resistant gene (Bioschi Biotechnol Biochem.; 64(7): 1416-1421 (2000), JP 2000-308491 A); or genes expressing auxotrophy such as argB (Agric. Biol. Chem. 51 (9), 2549-2555, 1987), niaD (Gene 111(2), 149-55, 1992 Feb. 15), or pyrG. (Curr. Genet. 16 (3), 159-163, 1989).